1. Field of the Invention
The invention relates to a circulatory microorganic deodorizing system for decomposing offensive odor constituents of exhaust gas through the agency of microorganisms.
2. Description of the Related Art
With a well known deodorizing system a of this type as shown in FIG. 10, exhaust gas containing dust, offensive odor constituents, and so forth is fed below a deodorizing layer c of a tower main body b, filled with activated charcoal as a deodorizing agent, dust, and water soluble offensive odor constituents are removed from the exhaust gas by showering thereon with process water w supplied via a water supply system wr from a water reservoir d to be replenished as necessary, and the exhaust gas after subjected to a primary treatment is passed through the deodorizing layer c for deodorization.
In the deodorizing system a of this type, however, since dust, and water soluble offensive odor constituents are removed simply by showering the process water w in droplet form on the exhaust gas g, dust and like, and water insoluble offensive odor constituents, which have not been removed, will ascend in the tower main body b, reaching the activated charcoal in the deodorizing layer c.
While the water insoluble offensive odor constituents, and the like are adsorbed to pores of the activated charcoal, and the exhaust gas g after deodorized is emitted into the atmosphere, clogging of numerous pores of the activated charcoal occurs due to adsorption of the water insoluble offensive odor constituents, and the like to the pores with the result that functions of the activated charcoal for adsorption and deodorization are degraded. Consequently, the deodorizing system described has had a drawback of requiring periodical replacement of the activated charcoal.
Further, although the activated charcoal has strong power of adsorbing and holding methanethiol, sulfur compounds such as methyl sulfide and the like, alcohol, fatty acids, hydrocarbon halide, aliphatic hydrocarbon, aromatic hydrocarbon, ester, and the like, it hardly adsorbs formic acid having one carbon atom, formaldehyde, methyl alcohol, propane, methyl chloride, and the like while it has only small power of adsorbing ammonia, hydrogen sulfide, the like.
Consequently, the system has had a drawback that sufficient deodorization of exhaust gas containing various offensive odor constituents could not be achieved because it has been difficult for parts of the offensive odor constituents to be adsorbed to the activated charcoal even if other parts thereof could be adsorbed.